Hi Claudio, I love your patch! Yet something to improve: [auto build test ERROR on s390/features] [also build test ERROR on kvm/queue v5.16-rc3 next-20211203] [cannot apply to kvms390/next] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Claudio-Imbrenda/KVM-s390-pv-implement-lazy-destroy-for-reboot/20211204-010121 base: https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git features config: s390-randconfig-r034-20211203 (https://download.01.org/0day-ci/archive/20211204/202112041017.COolnLgE-lkp@xxxxxxxxx/config) compiler: s390-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/c2d394c61e53062a1e7ba537029dce61f7a75cff git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Claudio-Imbrenda/KVM-s390-pv-implement-lazy-destroy-for-reboot/20211204-010121 git checkout c2d394c61e53062a1e7ba537029dce61f7a75cff # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=s390 SHELL=/bin/bash arch/s390/kvm/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): arch/s390/kvm/pv.c: In function 'kvm_s390_pv_init_vm': >> arch/s390/kvm/pv.c:257:17: error: implicit declaration of function 'mmu_notifier_register'; did you mean 'mmu_notifier_release'? [-Werror=implicit-function-declaration] 257 | mmu_notifier_register(&kvm->arch.pv.mmu_notifier, kvm->mm); | ^~~~~~~~~~~~~~~~~~~~~ | mmu_notifier_release cc1: some warnings being treated as errors vim +257 arch/s390/kvm/pv.c 212 213 int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc) 214 { 215 struct uv_cb_cgc uvcb = { 216 .header.cmd = UVC_CMD_CREATE_SEC_CONF, 217 .header.len = sizeof(uvcb) 218 }; 219 int cc, ret; 220 u16 dummy; 221 222 ret = kvm_s390_pv_alloc_vm(kvm); 223 if (ret) 224 return ret; 225 226 /* Inputs */ 227 uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */ 228 uvcb.guest_stor_len = kvm->arch.pv.guest_len; 229 uvcb.guest_asce = kvm->arch.gmap->asce; 230 uvcb.guest_sca = (unsigned long)kvm->arch.sca; 231 uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base; 232 uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var; 233 234 cc = uv_call_sched(0, (u64)&uvcb); 235 *rc = uvcb.header.rc; 236 *rrc = uvcb.header.rrc; 237 KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x", 238 uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc); 239 240 /* Outputs */ 241 kvm->arch.pv.handle = uvcb.guest_handle; 242 243 atomic_inc(&kvm->mm->context.protected_count); 244 if (cc) { 245 if (uvcb.header.rc & UVC_RC_NEED_DESTROY) { 246 kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy); 247 } else { 248 atomic_dec(&kvm->mm->context.protected_count); 249 kvm_s390_pv_dealloc_vm(kvm); 250 } 251 return -EIO; 252 } 253 kvm->arch.gmap->guest_handle = uvcb.guest_handle; 254 /* Add the notifier only once. No races because we hold kvm->lock */ 255 if (kvm->arch.pv.mmu_notifier.ops != &kvm_s390_pv_mmu_notifier_ops) { 256 kvm->arch.pv.mmu_notifier.ops = &kvm_s390_pv_mmu_notifier_ops; > 257 mmu_notifier_register(&kvm->arch.pv.mmu_notifier, kvm->mm); 258 } 259 return 0; 260 } 261 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx